Vol. 118 No. 1 (2022)

Sulfoxides are widely used in asymmetric synthesis due to their high efficiency as chiral inducers in numerous transformations. This article highlights the most significant contributions to the field of asymmetric synthesis with sulfoxides developed in the research group at the UAM. Total synthesis of natural products using diastereoselective reductions of β-ketosulfoxides, Diels-Alder reactions with 2-p-tolylsulfinylquinones or conjugate additions as key steps, are included. The reported synthetic approach to enantiopure helicenequinones is also revised. New uses of sulfoxides in the design of enantiopure molecular switches, are also shown.

Keywords: Sulfoxides, quinones, p-quinols, total synthesis, sulfinyl azobenzenes

Aromatic trifluoromethylation enabled by metal complexes is highly challenging yet extremely relevant for drug discovery and agrochemical design. First discovered in 2010, the oxidative trifluoromethylation represents an original approach to these valuable chemicals (aryl–CF3 ) and involves the key participation of late transition metals in high oxidation state, in particular coinage metals (CuIIICF3 and AgIIICF3 species). We herein provide a general overview on this topic, and compile the main contributions regarding the oxidative trifluoromethylation of arylboron derivatives mediated by well-defined CuIII and AgIII complexes.

Keywords: Trifluoromethylation, C–CF3 Coupling, High Oxidation State Organometallics, CuIII, AgIII

Coumarins are of great interest mainly due to their numerous biological applications. Trans-o-hydroxycinnamic acid, its esters and amides are suitable starting materials for the synthesis of coumarins, which requires prior E-Z isomerization of the double bond followed by a cyclization step. Such isomerization can be carried out, among other methods, through a photochemical process in the presence of a sensitizer, either initiated by UV light or mediated by visible light using organic or transition metal photocatalysts or in the absence of a photocatalyst taking advantage of a UV-Vis bathochromic displacement of o-hydroxycinnamates under basic conditions.

Keywords: Hydroxy cinnamates, photocatalysis, cyclization, coumarins, polymers

On the occasion of the RSEQ Award for Distinguished Career, the author describes her contribution to polymer research and its evolution throughout her more than 45 years of profession in which she has combined scientific and technological challenges. The work includes the study of the thermal degradation of polyvinyl chloride (PVC), the transition to modification reactions in solution, in the molten state (extruder) and the surface modification reactions of some polymers. It ends with her most current contributions in the field of nanoscience and nanotechnology.

Keywords: polymer degradation, chemical modification, surface modification, melt modification, nanostructured polymers

The computational modelling of physical-chemical properties, (eco)toxicity and environmental behaviour of pesticides and their transformation products, is on the verge of becoming a key tool to help in the pesticide risk assessment within the European legislative framework regarding these compounds. In this sense, this work aims to provide an overview of why there is interest in these tools with great potential for prediction by risk assessment agencies for the use of pesticides. Moreover, a practical example of its possible contribution to the risk assessment of these compounds is shown.

Keywords: pesticide, risk assessment, computational chemistry, alloxydim

On the occasion of the International Year of the Periodic Table of Chemical Elements (IYPT) one of the main actions undertaken by the Sección Territorial de Madrid de la Real Sociedad Española de Química (RSEQ-STM) was the design of a deck of cards with chemical elements and scientists. On the meantime, two trial sessions were carried out in both Primary and Secondary courses as a final stage of the project process. The aim of this article is to describe the stated deck of cards and, in addition, to show the results of the educational sessions. The pack of cards, which has not been commercialized for sale, has been distributed in educational and outreach events related to the RSEQ-STM.

Keywords: periodic table, deck of cards, educational tool, gamification, learning

A Chemistry experiment is suggested to students aged 13-16. It consists of coating with zinc the copper surface of a 5 cent euro coin. A second step is transforming the result obtained into brass. The density of the coin is determined and the mass of zinc covering it is measured. The experience reinforces simple measurement procedures and introductory chemical concepts including alloys, solutions or chemical transformations. As an extension for higher education, the proportion of Zn in the brass obtained can be estimated.

Keywords: 5 cent euro coin, zinc coating, alloy, brass, metal magnetism